Gas purification process and apparatus



Sept. 8, 1931. G. E. sElL GAS PURIFICATION PROCESS AND APPARATUS Filedl May 7, 1926 2 Sheets-Sheet 1 Sept. 8, 1931.V G. E. SEIL A GAS PURIFICATION PROCESS AND APPARATUS Filed May. 7, 1926 2 Sheets-Sheet 2 IUDONLI {Bral-3W INVENTOR W A'I'I'ORNEYs ltatented Sept. 8, 1931 narran sans raar rFicE GILBERT E. SEIL, OF NEVIARK, Nlll JERSEY, ASSIGNOR TO KOPPERS COMPANY, F PITTSBURGH, PENNSYLVAA, A CGBPQRAEEI GF EENNSYLVANIA GAS PURFGATION-ERCCESS ,AND APERATUS Application filed May his invention relates to process and apparatus for the treatment et gas, more particularly fuel gas, such as coal gas or other lo as an alkaline agent for effectingV the said purification, and the liberation oi' the sulphur, originally present in the gas as hydrogen sulphide.

",lhe invention further consists in such other n-ew and useful improvements, and has for -urtlun' objects such other operative advantages Vor results, as may be found to obtain in the process or apparatus hereinafter described or claimed. Y

in lthe copending application tor United Letters Patent of Frederick W. Sperr, 1 No. 69,929, filed Nov. i8, 1925, there i ribed and claimed process and apparatus Jor purifying gas from hydrogen sulphide, wherein the ammonia contained by the gas, or ogher ammonia introduced to the saine, serves as the alkaline agent wherein is suspended a ferrie compound capable ot converting hydrogen sulphide absorbed ly the said agent into tree sulphur when aerated; the said aeration revivies the suspension for 'further use. ln processes of this character,fnieans must be provid-ed for caring for the ammonia, which would ordinarily be liberated in the aeration stage, ln said Sperr application, 'the ammonia absorbed by the neutral suspension et 'ferrie compound in Contact with the gas is removed by distillation, and the het, sul'is'tantially neutral, sul

phided ciiiuent is aerated with finely co1n` lninuted air, with resulta-nt separation of free 'sulphur and rcvivilication of the sus` pension, which is then cooled and returned to contact with unpuritied gas.

rihe present invention provides means for utilizing the ammonia present in the ,das as au alkali. nf'ithout the necessity for distille tion of the sulphided liquor after Contact wi'h the and prior 'to the aeration stage. According to the present invention, l `introiaze. sei-iai no. leases.

duce the alkaline sulphidefd liquors, after contact with the gas, directly into the aeration rlhe aeration is preferably conducted in closed chamber, and the ammonia liberated by the action 01 the air used for aeration is subsequently recoveredvby suitable absorptive means. i Notwithstanding the tacit that my aeration apparatus is closed in such manner as to prevent the escape of ammonia or other gas .of noxious character into the atmosphere, I have provided means for access all parts thereof, as for example to the aeration media, that may be subject under actual conditions to stoppages or failure which necessitate removal and cleaning or replacement.

in the accompanying drawings forming a part et this specification and showing for purpo es oit' exemplilication 'certain form and manner in which the invention may be embodied and practiced but without limiting the claimed invention speciiically to such illustrative instance or instances:

,Figure l is an elevational view, parts being `shown in section, of apparatus adapted to eliect the removal of hydrogen sulphide from a gas containing ammonia, said apparatus including means for effecting absorption of the hydrogen sulphide and ammonia in a liquid, means for removing,` aerating, and recirculatingl the said liquid, and means tor disposing of the ammonia liberated in the course of aeration of the said liquid;`

2 is a top plan view ofthe aeration apparatus shown in Fig. l; l

Fig.' 3 is a perspective sectional view of the said aeration apparatus, parts being broken away to give a clear view of certain details for example the combination of distributive and contact means described and claimed. in copending application of Frederick W7. Sperr, Jr., Ser. No. 21,980, filed April 9, 1925. A substantially neutral suspension of an iron compound, as for instance, a 1.0 per cent suspension of ferrie hydrate, is introduced to the absorber A through the sprays 12, and travels downward through the absorber, coming into intimate contact with the rising gas. Ammonia present in the gas dissolves in the said liquid, rendering the same alkaline, and facilitating the absorption of hydrogen sulphide from the gas, which gas then leaves the absorber A through the conduit 13, substantially free from such noxious constituent. The absorptive liquid becomes sulphided through contact with the gas, and upon reaching the bottom of the absorber A, passes through the sealed outlet line 14 Vto the header l5, from which it is distributed into the compartments T1,T2,etc., of the aeration apparatus T, that is for convenience hereinafter designated as actiiier T. The construction of said a-ctifier is shown more clearly in Fig. 3. In the present instance, the actiiier is comprised of two compartments T1 and T2, but a single compartment, or any number of compartments, may be employed, as may be convenient in accordance with the amounts of gas and/or liquid handled. Vithin each of the said compartments Tl, Tg, ete., are situate a plurality of baiiles 16, so positioned as to cause the said compartment to be divided into a number of passes, through which the liquid passes, traversing each pass in opposite direction to its passage through the adjacent passes. The header 15 is preferably arranged so as to communicate through the valves 1S and pipes 17 to the compartments of the actiiier, the liquid entering at similar corners of each compartment. Thus, the partition 19 between two compartments of the actiiier T is adjacent to the last pass traversed by the liquid in one compartment, as for instance T1, and is adjacent the first pass traversed in the adjacent compartment T2. Ordinarily, the two compartments T1, TL are operated in parallel, but by opening a passage in that part of the partition 19 which is adjacent to the inlet side of the actier T, the compartments may be operated iu series. ,lVithin each pass of the actifier, and parallel to and slightly above the bottom thereof are. situate a plurality of vibratile tubular fabric aerators 47, such as those described and claimed in my copending application Ser. No. 21,978, tiled April 9, 1925, which diffuse finely comminuted air into said liquid. Said aerators 47 are provided with air through the individual feeders 20, which in turn communicate with the air headers 21, of which there is one foi` each compartment of the actifier, and which are supplied with air from the blower 22 and air main 23. The air supply to each compartment may be shut off or regulated by turning one of the valves 24. The liquid in the actiiier is maintained at a suitable depth of, say, three feet, and under the influence of the finely comminuted air introduced through the aerators 47, is rapidly and efiiciently revivified, with sepa- `Ltion of sulphur as free sulphur. The acration is usually conducted in such manner as to cause the said sulphur to float upon the surface of the liquid; the maintenance of such a foam is beneficial in that it serves as an effective means of scrubbirg the air leaving the surface of the liquid, and thereby removing any hydrogen sulphide and/or analogous noxious volatile impurity entrained by such air. The excess of foam is allowed to flow through the weirs 25 into the foam trough or launder 2G extending along the entire length of the actiiier, and from which the sulphur foam or sludge may be removed through the Valve 27 for further treatment as desired.

The air used for aeration of the sulphided ammoniacal liquid will carry with it as it leaves the surface of the said liquid, substantially all of the ammonia present. In order to prevent the escape of ammonia into the atmosphere about the actiiier and to make possible the recovery of such ammonia, I have provided a covering or enclosing means for the actifier, and means for drawing off the ammonia-laden air, and I have so designed the said enclosure as to provide for easy access to the interior of the said actiiier, when desired. Such means for access to the interior consists in part of the removable covers 28, of which there may be any convenient number for each compartment of the actifier. ln the present illustrative embodiment of the invention, two are. shown for each compart-ment, and as shown in Fig. 3, those which relate to the compartment T1 have been removed and are not shown. For convenience in removing the said covers 28, I provide the lifting eyes 29, that are adapted to receive a hook suspended from a crane, or other lifting means.

For removing the ammonia-laden air, I make use of the foam trough or launder 26, which is integrally covered by means of the cover 30 (shown partly cut away in Fig. 3). Trough 2G is connected by means of conduit 31 with the intake side of the exhauster 32. The slots 33 are provided in the said cover 39 immediately above the weirs 25, to allow for the insertion of the stops or gates 34C that serve to shut off the flow through said weirs 25, when the gates 34 are inserted through the solts 33 to rest in the supports 35. The said gates 34 are useful when it is desired to gain access to one compartment of the actifier while others are in operation, as their insertion prevents any reduction of suction in the Weirs of the other operating compartments.

The revivilied liquid flows out at the bottom of the actier and enters the header 36, flowing thence vthrough the line 37 into the sump S. From the sump S, the liquid is pumped by pump 38 through line 39 and sprays 12 into the absorber A, thus recommencing the cycle of operation. Additions of fresh iron or other compound are made as necessary.

The ammonia-laden air leaving the actifier is conductedby the eXhauster 32 through line 31 and enters the absorber B, that is filled With permeable contact means. Water or acid is introduced into the absorber B through the sprays 40, and comes into intimate contact With the rising ammonia-laden air, absorbing the ammonia present in the air. The air, freedof ammonia in this manner, escapes through the stack 4l, While the am- -moniacal solution leaves the absorber B through the line 42 to be recirculated back to absorber B by the pump 43 through line 46 and sprays 40, or to drain into the tank 44. Fresh Water or acid or other absorbent may be added to the system from the tank 45. The saturated solution in tank 44 is Withdrawn when desired for recovery of the ammonia. Such recovery may be accomplished by any of the Well-known means which is suitable for the treatment of the ammonia in the form in which it has accumulated.

IVhile I have described and illustrated my invention in a particular :t'orm and embodiment, I may modify the application thereof with respect to its several details. For eX- ample, I may vary the arrangement of aerators 47, baies, and the like, Within the actilier T, or I may employ other types of aerators 47, as for instance, Filtros plates, and the like. Or the ammonia-laden air may be otherwise removed from the said actiier T,V

and/or otherwise treated for recovery of the ammonia, as for instance in a saturator.

Moreover, I may vary the percentagev o suspended compound in the primary absorbent liquid, and I may substitute for the said iron compounds other compounds of metals the sulphides of which are insoluble, such as compounds of nickel, cobalt and manganese. In case such, or other compounds, are shown to have a catalytic edect upon the reactions involved in the absorption of hydrogen sulphide, they may be used in far lesser quantities than those Which are-known to be reactive in effect.

The invention as hereinabove set forth is embodied in particular form and manner but may be variously embodied Within the scope of the claims hereinafter made.

I claim: Y

1. A process ot' .removing hydrogen sul-` phide from gas containing ammonia, consisting in: subjecting the said gas to contact Witha Wash liquor containing in suspension an iron compound, in such a manner as to cause the said Wash liquor to absorb ammonia from the gas, thereby facilitating the removal of said hydrogen sulphide from the gas by the said iron compound; continuously removing the suspension and aerating theV said ammoniacal liquid containing the sulphided iron compound out of contact With the gasto liberate free sulphur and driveoiip ammonia therein concurrently; returning the i reimwine` the suspension and aerating the said ammoniacal liquid containing the sulphided iron compound out of contact With the gas to liberate free sulphurand drive o ammonia therein concurrently; returning the thereby reviviiied liquid containing theV reviviiied iron compound to contact with freslrquantities of gas; removing the air laden with ammonia during the course of aeration; and treating such air to recover ammonia therein. i

In the purification ot gas with an ammoniacal suspension of an iron compound the steps which consist in: aerating the ammoniacal sulphided suspension to liberate free sulphur and drive oil ammonia therein concurrently and removing the ammonia liberatedin the course or' saidcaeration.

4. In the purification of gas with an ammoniacal suspension of an iron compound the steps which consist in: aerating the ammoniacal lsulphided suspension to liberate free sulphur and drive off ammonia therein concurrently; removing the ammonia liberated in the course of Vsaid aeration; and recovering the ammonia.

5. In the purification of gas With an ammoniacal suspension of a metal compound which forms' anV insoluble sulphide capable of oxidation in aqueous suspension the steps which consist in: aerating the sulphided suspension to liberate free sulphur and drive olin ammonia therein concurrently; confining the ammonia-laden air rising from the liquid; and treating such air to recover ammonia therefrom.

6. In the revivilication of spent ammoniacal liquids used 'for gas purification purposes, the improvement Which consists in aerating theV said ammoniacal liquids in a closed system to prevent escape of ammonia. therefrom into the atmosphere, drawing olil -from seid closed system air containing ammonia, and subsequently removing the ammonia from said air.

7. The process of removing hydrogen sul-- phide from ges which also contains unmonia, consisting in: Washing the gus with We.- ter containing in solution or suspension a metal compound which forms an insoluble sulphide capable of oxidation in aqueous sus-- pension; continuously disclnirging und aeretingsuch Wash liquor utter its Contact with such ges und While containing both ommonin and the insoluble sulphide to liberate 'free sulphur and drive ofi ammonia therein concurrently; Washing such nir, alter it has passed through such spent Wash liquor, to absorb the ammonia 'from such air; und returning 'the ammonia tree gus Washing liquor containing the regenerated met-el compound for further Contact with gas.

8. The process of removing hydrogen sulphide from which also contains ammonia, consisting in: Washing the gus With u ivo-.sh liquor containing a compound ot a metal Whose sulphide is insoluble, to remove ainmoniu and hydrogen sulphide from the gas; ueruting such spent Wash liquor utter its Contact with `such gus und While containing bothnmmoniu und the insoluble sulphide to liberate free sulphur und drive oli ammonio therein concurrently; removing ammonia from aereting nir and freeing the liquor of i'ree sulphur and returning the aeruted Wash liquor containing such compound, free of ammoniau und free sulphur, for further contact with gas.

9. A process as claimed in claim 7 and in which the aeration is effected With finely comminuted air.

10. A process es claimed in claim 8 and in which the aeration is efi'ected With finely comminuted air.

'11. A process of removing vhydrogen sulphide from ges containing it and also containing ammonio, consisting in: Washing such gas With :i Wash .liquor and thereby removing ammoniafrom the ges and forming :in ammoniacal liquor Whjch absorbs hydro gen sulphide from the same gas; continuouslydischarging the Wash liquor and aerating such Wash liquor While containing` ubsorbedemmonia and u compound or" o metal which iforms en insoluble sulphide so as to liberate the sulphur of such hydrogen sulphide as free sulphur and drive off ammonio therein concurrently; recovering ammonio. from such eerating air; und returning the uerated vWalsh liquor, free of zunmonie und tree sulphur, to Wash further 12. A process as claimed in claim 11 und in `which -the Washing of the ges und the nera-tion of the Wash liquor is eliected While e. compound ot a metal Whose sulphide is insoluble is'present in the Wash liquor, and in .which the aeration is eilccted with linely comminuted oir.

18. ln :i process for purifying gases ol" hydrogen sulphide involving the use of ammonia as the alkali und involving the use of e metallic compound which effects liberetion of sulphur as free sulphur during ucraition or" spent Wash liquor, the improvement consisting in the steps or concurrently liberating the sulphu es free sulphur und driving oli' the ammonia in the spent liquor by ucruting the spent liquor While the ammonia und sulphide ure both contained in the spent liquor and absorbing free ammonia from the :ierating nir.

l/l. in :i process for purifying gases oit hydrogen sulphide involving `the use of ummonin as the alkali und involving the use of e. metallic eomponinil which eliects liberation of sulphur as tree sulphur during aeration of spent Wash liquor, the improvement consisting in the steps of concurrently liberating the sulphur :is :tree sulphur and driving oli the ammonio. in the spent liquor by eci-utinjj the spent liquor While the ammonia und siuphide ure both contained in the spent liquor und washing the air to remove ninmonia therefrom'.

l5. ln :i process for purifying g'iscs of hydrogen sulphide involving the use of :unmonie. es the ullmli and involving` the use oi u metullic compound which effects liberation of sulphur tree sulphur during aeration o spent wesh liquor, the improvement consisting in the steps of concurrently liberoting the sulphur as free sulphur und driving oli the ammonio in the spent liquor by :territing the spent liquor While the unnnonia und sulphide are both contained in the spent liquor and Washing the nir with en acid to remove the ammonia from the nir.

16. ln e process for purifying el hydrogen sulphide involving` the use ot ummonia es the :illruli und involving the use ol' e metullic compound which cliects liberotion of sulphur es free sulphur during ucration of spent wesh liquor.v the impl-evenmin, consisting in the steps oit concurrently liberating the sulphur es free sulphur en d driving ofi the ammonia` in the spent liquor by aerating the spent liquor While the ammonio and sulphide are both contained in the spent liquor und Washing the nir with :L circulating vrash liquor to remove the ammonia 'from the nir, said Wash liquor containing um monie. previously washed from the uir.

l. The process ot removing hydrogen sulphide :from ai gus contnining ammonio, which comprises: sl'lbjecting the gus t-o Contact with u cool und substuntiully neutral suspension of n. metallic compound, cu iuble ot ebsorbing ammonio and hydrogen sulphide from the gas, removing the suspension und aerating it to liberate free sulphur ond to drive oil7 the ammonia therein, and returning the substantially neutral suspension to contact with gas. Y

18. Apparatus for purifying gases comprising, in combination: an absorber; gas inlet and outlet means therefor; an actifier tank for said absorber adapted for containing a body of liquid therein; means for maintaining a circulation of liquid back and forth between said absorber and said actifier; said means being adapted to deliver liquid from the absorber to the actifier at the lower part thereof; means for forcing gasinto a body of liquid in said actifier tank at the lower part thereof; means for collecting and removing solids f1 om a body of liquid in said actier tank at the upper part thereof; a second absorber for gas from said actifier; and enclosed means for conducting gas from the upper part of said actifier tank to said second absorber.

19. Apparatus as claimed in claim 18 and including enclosed means for recirculation of washing liquor through said second ab-.

sorber.

20. Apparatus for purifying gases with washing liquid and for actifying said liquid comprising; in combination: an absorber; an actifier tank; means for circulation of liquid to and fro between said absorber and said tank; a trough for said tank and in communication therewith nearer the upper than the lower limits thereof; a cover for said tank for sealing it from the atmosphere; and a Conduit vfor confining and leading gases from said trough.

21. Apparatus for purifying gases comprising; in combination: an absorber; on actifier comprising a plurality of compartments; means for circulation of liquid to and fro between said absorber and actifier; removable covering means -for each of said compartmentsand each adapted for sealing their respective compartments; a trough common to a plurality of said compartments; a` cover for sealing said trough; inlet means respectively below said cover and said cover ing means for leading material from each of said compartments, respectively, into said trough; inlet closure means for shutting off each of said inlets from said trough during removal of the covers from their respective compartments and a conduit for confining andleading gases from said trough.

22. Apparatus for purifying gases com prising, in combination: an absorber; an actiiier comprising a plurality of compartments; means for circulation of liquid to and fro between said absorber and actifier; removable covering means for each of said compartments and each adapted for sealing their respective compartments; a trough common to a plurality of said compartments; a cover for sealing said trough; inlet means respectively below said cover and said covering means for leading material from each my hand.

GILBERT E. SEIL. 

